Shere Hite, the feminist and sex researcher famous for her groundbreaking report into female sexuality, asks if we have to talk about sex for the entire interview. "That's not all that I am about, you know," she says.

The Hite Report: A Nationwide Study of Female Sexuality catapulted the then unknown graduate student to instant fame when it was published in 1976. Based on responses from 3,500 women to questionnaires about their experiences of sex and pleasure, some 50m copies have been sold worldwide. Yet, although many of the findings – specifically the importance of the clitoris for a female orgasm – are now widely accepted, the report was hugely controversial and earned Hite some highly critical press coverage.

"I was saying that penetration didn't do anything for women and that got some people terribly upset," she says now. "Men heard about this thing that the first book said, that they weren't doing it right in bed, and that made some media moguls angry."

Despite her role in feminist research, Hite has attracted controversy from both sides. To support herself through college in the early 70s she posed nude for Playboy as well as for an ad that saw her draped over a typewriter with the words: "The typewriter so smart she doesn't have to be." She subsequently attended a meeting protesting at the sexist ad and has pointed out that she needed the money to pay for a history degree at Columbia.

Explaining the controversy stirred by her first book, she says: "I was the only sex researcher at that time who was feminist. I tried to extend the idea of sexual activity to female orgasm and masturbation."

Before the Hite Report, sexologists such as Freud and Kinsey propounded the view that "proper vaginal orgasms" could only come about with penetrative sex. Hite's work showed that 70% of women who do not have orgasms through intercourse, or the "great male thrust", are able to do so easily by masturbation. The research upset the status quo, and many of her critics attempted to discredit Hite's findings by claiming that her methods of evidence gathering were unscientific and based on too few responses. This, says Hite, upset her the most.

"I feel I have contributed significantly to methodology. None of the media read the long explanation in my report of how I did the research," says Hite. "After all, Freud only interviewed three Viennese women."

She went on to write The Hite Report on Men and Male Sexuality (1981) and her most radical work, Women and Love: A Cultural Revolution in Progress (1987). The attacks continued and became more vehement. Hite endured death threats in the post and by phone. Paparazzi would jump out of bushes to photograph her outside her home. Time magazine slated Hite and her work on its cover, leading a dozen well-known feminists, including Gloria Steinem and Barbara Ehrenreich, to issue a statement condemning the media hostility towards Hite's work, claiming that it was tantamount to a "feminist backlash and against the rights of women everywhere".

Unable to cope with the increasingly personalised attacks, Hite eventually renounced her US citizenship in 1995 and swapped it for a German passport. She has lived in Europe ever since, most recently settling in London, a city she loves.

Now in her late 60s, she is still beautiful although surprisingly frail. Hite speaks several European languages and loves the fact that her work is far better received here than in the US. "I am so thrilled to meet young feminists here," she tells me. "They seem to still think my work is relevant."

Born in the bible belt of America to a 16-year-old mother, Hite was raised by her grandparents and then her aunt and wrote about her need for recognition in an autobiography. "It must have been horrible for [my mother]. She left me with her mother but she always told me the truth. She resented having to raise me and called me her cross to bear."

Despite her earlier insistence that we shouldn't focus only on sex, Hite keeps returning to it. "Penetration stimulates men but not women. I don't see why the walls of Jericho didn't fall down after I said that, because it makes total sense." We are in a quiet restaurant, and Hite's comments cause the waiter to blanch. She is entirely un-selfconscious about discussing such matters in public.

A curious mix of modesty and self-importance, Hite believes that her work continues to be a crucial component of the struggle for women's liberation. "What we really need is to make a film about me so we can see there is still a problem for women," she says. "I think the most important books published on feminism are my own."

"I stopped watching films 25 years ago because I realised that the film-makers had never read my books or books by any other feminist so I thought I wouldn't watch any of their work either."

Hite's current project is writing a screenplay about her life. "Writing about myself is not easy. I wish someone had told me how difficult it would be before I started."

Aside from scriptwriting, Hite contributes a weekly column for a Venezuelan broadsheet and says she answers every single response from readers. "Lots are from young men who want to know what they are doing wrong."

Hite says she is "fascinated" by scientific progress in the field of older women's fertility, with egg donors and surrogate carriers. "There is a terrible stigmatisation of older mothers. Maybe women should put off having children until they are quite a bit older." She even says that she may consider having a baby.

Has feminism progressed since the publication of the Hite Report? "Yes," she says. "But we have to ask why men are still saying, 'She's a bitch', 'she's a whore', 'she's neurotic', 'she's abnormal'." Have men said this about her? Hite does not answer but, as we prepare to leave, she touches me on the arm and looks me in the eye. "Because I have sold a lot of books I think that women think that I'm fine, but I'm not fine. I hope they realise that."